Effects of Crack Formation on the Mechanical Properties of Bilayer Graphene: A Comparative Analysis

TT Yu and JY Li and ZQ Yang and HP Li and Q Peng and HK Tang, CRYSTALS, 13, 584 (2023).

DOI: 10.3390/cryst13040584

We present a molecular dynamics simulation study on the effects of crack formation on the mechanical properties of bilayer graphene. Bilayer graphene possesses unique electronic properties that can be modified by applying a voltage, making it an attractive material for various applications. We examined how the mechanical properties of bilayer graphene vary under various crack configurations and temperatures, measuring Young's modulus, fracture toughness, fracture strain, and fracture stress. We compared the effect of crack presence on single and both layers and found the appearance of double peaks in the stress- strain curves in the case of a monolayer crack, indicating a subsequent fracture of the cracked layer and the uncracked layer. We also examined the effect of crack shape, size, and orientation on mechanical properties, including circular, hexagonal, and rectangular cracks along two axes. We found that both circular and hexagonal cracks had a smaller Young's modulus and toughness than rectangular cracks, and the orientation of the crack had a significant impact on the mechanical properties, with a 2.5-times higher toughness for cracks with a length of 15. Additionally, we found that Young's modulus decreases with increasing temperature in bilayer graphene with cracks on both layers. Our findings provide valuable insights into the potential applications of bilayer graphene in the design of advanced nanoscale electronic devices.

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